Not only does Algert exist, but also Algerter. If these names are not connected to Alger, I would be very surprised. The formation of family names by dropping off parts of the original name, is indeed common.Algerter/Algert/Alger are no doubt Germanic names, but to find out if the immigrants to the US came from France or somewhere else requires a research. France is a Germanic country anyway, even if they have corrupted their languge to the extreme. Regards.